Tektronix 465 Repair and Restoration

[ModemHead]

After buying and refurbishing some older Fluke DMMs for use on my workbench during the past couple years, I recently decided to try something a little more complicated. So I found a crusty old "parts or repair" Tektronix 465 on eBay. It looked physically intact and the pix showed that it at least made a dot when the beam-finder button was pushed. Good enough, so I set about to win the auction.

The scope arrived safe and sound since it was well-packed. And yep, it was a bit dirty and pretty much dead. Looks as if it has spent the last 20 yrs in someone's garage.



Looking inside: The sweep/trigger board, with the timebase board behind it. Power supply transformer and filter caps are visible towards the rear.



The vertical amp board is on the other side.



The power supply, high-voltage, horizontal deflection and calibrator circuit are on the bottom board:



The vertical deflection driver is nestled in beside the CRT neck.  Lots of flying leads and point-to-point construction on the output. I won't be touching this unless absolutely necessary.



Powering it on, I got a dot when I pressed the beam-finder, and that was it. Checked all the power supplies, all of them are pretty much spot-on with no ripple to speak of. All of the transistors are socketed, so since there were some signs of oxidation, I re-seated every transistor I could get my fingers on. Horizontal sweep appears! Looks linear and perfectly normal. But no vertical deflection at all, including the position controls. And the intensity control has to be turned all the way up to see anything. Which leads to the trace disappearing at higher sweep speeds.

The Tek 465 has a "trigger view" switch which basically disconnects both vertical amps and instead connects the vertical deflection driver to a trigger signal sample from the sweep/trigger board. It's a cam and leaf arrangement built right onto the PC board. Punching this switch vigorously showed some noisy vertical deflection. Examining the switch I can see some crud in it.



So I cleaned it by soaking a paper strip in IPA and moving it back and forth between the contacts.



Vertical deflection now looks pretty good, so on to the intensity problem. Selecting either the "Mix" or "A-intensified" horizontal modes should result in the delayed section of the sweep being very bright. Instead, it seems this section is about the only thing readily visible. The regular part of the trace is just barely visible with the intensity turned to max. Not normal, but somewhat promising.

The high voltage supply is supposed to be -2450V. Checking it shows -2400V, so I tweaked the HV adjustment up a bit. The manual says the CRT grid bias should be adjusted for a dim dot in X-Y mode when the intensity control is set for a 20V output on the Z-axis (intensity) amp. Interesting, the Z-axis amp output will only go to 15V with the control at max. The Z-axis amp consists of 4 discrete transistors, so I check through it and can't find anything wrong. The inputs to this amp are several diode-ORed signals from various places.  Blanking inputs pull up, intensifying inputs pull down. So I start checking the blanking inputs, and when I get to the "Chopped Blanking" input, it looks fishy. Pulling the cable for this input results in a very bright trace!

Working backwards, the chopped blanking signal comes from a common-emitter transistor amp, which is fed from a small toroidal coupling transformer. It's supposed to provide beam blanking while the beam traverses from one channel to the other in chop mode. The transistor tests good, but is never turning on because it appears to have no DC bias. This results in the collector resistor pulling up the Z-axis input really hard. Found it! The secondary winding on the toroid is broken right in the middle. It appears to have taken a serious blow, perhaps from the case of the scope.



As a temporary fix, I scraped some enamel off of each broken end and made a little solder splice. I'll make a more permanent repair after locating some enameled wire to rewind the secondary.



Success... It's alive!



And happy.



Further checkout reveals no other major problem that I can find. Both vertical and horizontal calibration is a little off, but not too much. The front panel area needs serious cleaning, and of course all the vertical attenuator and timebase switch contacts as well. I'm pleased and somewhat surprised that the scope is operating this well without having to replace a single component (except for the bypass cap I broke with a pair of needle-nose pliers.)



Next up, some disassembly and cleaning...

Edit 1-July-2017: Photobucket sucks.

[Teknotronix]

Nice! It's great seeing some of these old scopes being cleaned up like new.

[ModemHead]

Yea, I find the work quite satisfying. Speaking of being cleaned up...

The front panel is grimy and the structural plate of aluminum behind it is suffering from oxidation/corrosion, especially around the holes. This scope has not seen a humidity-controlled environment in years...



After removing the sweep/trigger board, the timebase board is accessible.  This is the A and B timebase range control with the cover off. More delicate cam-and-leaf stuff to clean. I used more paper strips and IPA, then finished up with some Caig De-oxit for good measure.



The front panel was cleaned with IPA, then scrubbed with a toothbrush and baking soda toothpaste.  All the knobs and plastic bits got the same treatment.



More cleaning and dusting, resulting in a pile of scope bits to re-assemble.



Re-assembly started. Vertical amps and sweep/trigger boards re-installed. The front aluminum piece was cleaned with a Dremel tool with an emery wheel. No more corrosion.



Getting the pots, controls and front-panel bits back in order. The BNC jacks were cleaned with a Dremel tool with a wire brush attachment. At least on the outside, not sure how to get the inside part.



The old power cord was stiff, cracked and nasty-looking, so a new one has been re-installed. The old strain relief was cleaned and re-installed along with the new cord.



Re-assembly complete and ready to re-test.



The trigger-view switch acted up again. I cleaned it once more with IPA and also treated with some Caig De-oxit. It has behaved properly since then.



Nice sharp traces for an old scope.



The service manual has an extensive procedure for performance checks and calibration, so the next big thing is to go through that.  For now though, I think I'll just work on improving the appearance of the outer shell.  Does spray paint come in Tektronix blue?

Edit 1-July-2017: Photobucket sucks.  But the scope is still in service.

[tekfan]

Great work repairing this lovely scope. Just goes to show how reliable old components really are. Looks like this one is from the mid 70's or thereabout. Those big silicone coated non inductive resistors in the vertical amplifier always looked very strange to me.
I always find that cleaning the buttons and knobs is the most annoying task.

[ModemHead]

Thanks.  Those ceramic capacitors that look like wirewound resistors are strange to me. Of course, when this scope was made I was barely a teenager, whose favorite store was Radio Shack.

The most annoying task to me was cleaning all those switch contacts. I kept worrying that one wrong move and the game was over, if one of those little leafs got bent.

[w2aew]

Seriously nice job!

[Richard W.]

Wow, it looks really good. I'm impressed. But what's the trick behind the smiley? 
The scope doesn't seem to be in XY-mode at first sight...

[amspire]

Wow, it looks really good. I'm impressed. But what's the trick behind the smiley? 
The scope doesn't seem to be in XY-mode at first sight...

This photo might give you a clue:

[ModemHead]

Wow, it looks really good. I'm impressed. But what's the trick behind the smiley? 
The scope doesn't seem to be in XY-mode at first sight...

An even better clue: Set the B-sweep up to catch just the right parts of a square wave on CH 1 and a sine wave on CH 2, then display the A-sweep, with the B-sweep portion intensified. Turn the intensity way down so only the intensified portion is visible, and you have the "Happy Tek" version of the old "Happy Mac" self-test icon.

[lowimpedance]

 What a little beauty  , started my electronics life with the 465b as the main 'weapon of choice' so have a soft spot for it.
 I also like the modded fluke 8050 in the background. (noted from the other thread, which I have kept a copy of, will be quite useful when my 8050 lcd packs it in!).
I'm sure you had just as big a smile as the 465!!.

John

[alm]

Good work! I would be hesitant to take a wire brush to a BNC connector, since you'll strip of the plating. This is especially bad for silver plated connectors, since silver oxide is conductive, so you're unlikely to see any improvement.

[krivx]

Good work! I would be hesitant to take a wire brush to a BNC connector, since you'll strip of the plating. This is especially bad for silver plated connectors, since silver oxide is conductive, so you're unlikely to see any improvement.

Is there a better way, apart from just replacing the connector? I have a scope with pretty dark BNC connectors, I just sprayed them with contact cleaner and wiped away any loose crap. It works, but I'd be happier with cleaner connectors.

[ModemHead]

Good work! I would be hesitant to take a wire brush to a BNC connector, since you'll strip of the plating. This is especially bad for silver plated connectors, since silver oxide is conductive, so you're unlikely to see any improvement.

That's a valid concern. Although a Dremel wire brush is not nearly as abrasive as one might think. The readout actuator rings were intermittent before cleaning, they work well now.

Is there a better way, apart from just replacing the connector? I have a scope with pretty dark BNC connectors, I just sprayed them with contact cleaner and wiped away any loose crap. It works, but I'd be happier with cleaner connectors.

If it's really discolored, maybe one of those dry silverware polishing cloths might improve the appearance. Silver polish might work, but I'd be concerned about getting residue inside the connector.

[ModemHead]

What a little beauty  , started my electronics life with the 465b as the main 'weapon of choice' so have a soft spot for it.
 I also like the modded fluke 8050 in the background. (noted from the other thread, which I have kept a copy of, will be quite useful when my 8050 lcd packs it in!).
I'm sure you had just as big a smile as the 465!!.

John

Yep, I can understand the urge to be a scope collector.  Must... resist...

I have more detailed pix and information on the 8050A LED modification that I could post, if there's interest.

[Chris Wilson]

Wow, beautiful restoration, a credit to you.  I am the newbie with the poorly 475, as you are obviously intimate with these things may I ask you a question please? Driven off the spindle the Time / Division knob, inside the casing, is a microswitch, with a single round alloy ring with a peg sticking it of it. My microswitch moves little, if at all, whatever is done turning or pulling the Time / Division knob. I will get the meter on it later, and see if it actual changes state, I suspect not unless it's incredibly sensitively set. Can you briefly describe how the microswitch should be triggered, and what it does please? I have found other issues with mine that I will mention in the "Tek 475 is this likely to be a straightforward repair thread. That rebuild is lovely, I am very envious of your patience.

[alm]

I believe the resistance of silver oxide is quite low, so electrically cleaning is unlikely to yield much improvement. If you value appearance over function, I would probably also try something designed to clean silver, since it's less likely to remove the silver. Not sure if they leave some sort of non-conductive film you may have to remove.

[ModemHead]

Wow, beautiful restoration, a credit to you.  I am the newbie with the poorly 475, as you are obviously intimate with these things may I ask you a question please? Driven off the spindle the Time / Division knob, inside the casing, is a microswitch, with a single round alloy ring with a peg sticking it of it. My microswitch moves little, if at all, whatever is done turning or pulling the Time / Division knob. I will get the meter on it later, and see if it actual changes state, I suspect not unless it's incredibly sensitively set. Can you briefly describe how the microswitch should be triggered, and what it does please? I have found other issues with mine that I will mention in the "Tek 475 is this likely to be a straightforward repair thread. That rebuild is lovely, I am very envious of your patience.

You may ask any question you like, however you must know this is the first Tektronix brand scope I've ever taken apart or repaired.  But there are plenty of other knowledgeable folks here as well.

I examined the timebase switch on my 465 and I can't find a microswitch anywhere. This must be a difference between the 475 and 465.  I took a quick look at a downloaded 475 service manual and I cannot find a microswitch there either.  Is it by chance between the cam switch assembly and the vernier pot on the back end of the shaft?

Maybe someone owns, or has worked on, a 475 that can comment.

[Chris Wilson]

Thanks for replying, I have taken a photo of the switch. I have also had the knob off and there are two issues. In the photo, sticking through the alloy disc, you can see a headed pin. One of the pins on the back of the Time / Division switch depresses this floating pin when the knob is fully in. This floating pin pushes a rimmed white plastic bobbin, which in turn operates the arm of the microswitch itself. The pin was seized in the alloy bobbin. As well as this the copper plated spring clip which is on the same side of the flat face of the white plastic bobbin to the microswitch lever arm, but at 180 degrees around the periphery to it, is weak. I have freed the pin as well as I can without taking the board out, but it still sticks a little. I think the copper plated spring steel tab that assist retraction of the plastic bobbin with the knob pulled needs re tensioning. It seems it only controls the delay time function, so I doubt it's the crux of my problems, but it's another issue.

http://www.gatesgarth.com/TEK/microswitch.jpg

[ModemHead]

Definitely not in my 465.  If it has anything to do with pulling and then turning the sweep speed knob, then it is related to the B-sweep, which is not worth worrying about right now.  Just keep the white line on the sweep knob lined up with the black marks on the skirt, for now.

We should probably keep this discussion in your 475 thread. 

[Tedyp]

I am very impressed about the restoration. Looks like new!
I have 2 Teks : 465 and 465B. The 465B bought at early 80's, cost a fortune, but it worked fine 30 years!
Recently I had a major problem (465B), on the Horizontal Amp. I've downloaded tons of service manuals, looking for the horizontal amp. schematic - no way to find it. I found by chance that a capacitor was faulty - C4375 - and almost "killed" a resistor near it R4376, but I could not find the schematic anywhere.
Maybe, by chance someone have the FULL service manual? Including ASSY 10 (Horizontal amplifier) circuit?
I'll be very thankful for help.
Thanks in advance,
Tedy

[ModemHead]

Thanks. I recently installed new shelves over my bench and the 465 now occupies a prominent place there. Even though I have a better scope, I seem to enjoy using the 465 most. The controls produce a satisfying CLUNK! instead of softkey menus or the faint click of relays.

If you can't find a decent copy of the 465B service manual for free, I highly recommend Artek Media. I have two of their PDF manuals, and they're well worth the very low cost. High resolution and hyperlinked. When you zoom in on the diagrams you can actually read the fine print. If you have a concern about whether a particular diagram is included, an email to Dave at Artek will probably get an answer. He is active on the Yahoo TekScopes group.

[Tedyp]

Thank you very much ModemHead!!!
I've paid and d/led the manuals from Artek Media, and indeed, their manuals look complete.
I don't need them right now, as meantime I've fixed the problem, however sooner or latter, I am sure I'll need them.
Thank you again for assistance and good will,
Tedy

[steve_w]

Good job, brings back fond memories

[slateraptor]

Awesome work. Thanks for sharing!

[quint]

The service manual has an extensive procedure for performance checks and calibration, so the next big thing is to go through that.  For now though, I think I'll just work on improving the appearance of the outer shell.  Does spray paint come in Tektronix blue?

Sorry to be late in answering this question.  If you still need authentic Tek blue paint, check with Stan Griffiths.  He sells some spray paint made by the same company that does it for Tek at his web store: http://www.reprise.com/ash/clients2/Parts_Shop/misc.html

[ModemHead]

Thanks for that info, have filed it for future reference.  Although after scrubbing the shell thoroughly and flattening out the dents, I decided that even with a few scratches, it probably already looks better than it would after some amatuerish attempt by me to re-paint it.

[Spawn]

I don’t know about you, but I think it’s a electrician/electronics thing, when it comes to painting and working with wood, I hate it!

I would be happy with couple scratches  

That being said, I have to say you did tremendous job there man, I really love the dedication and making something so beautiful

[WurliTzerwilly]

Great restoration work. Looking good.

There's a difference beetween the 465 and my 465B, as I don't have the trig view button. It's a bandwidth limit switch instead, but no matter. 

I've had the 465B since the 1980s when I used it at Centronics where I worked. They 'donated' it to me when they were taken over by Genicom and we finally parted company.

The 'scope has had some use in all those years, but has been stored for a few years and I wouldn't be surprised if some electrolytics have dried out in that time. It was working fully when I loaned it to my son, but when he came to use it recently, there was no trace at all, even when the beam finder was pressed.

As an ex-TV repair man, having checked the power supply voltages, which are very close to tolerance, my instincts told me that there were probably no anode volts being produced, so I rigged up a rough probe with 10 Meg resistors and that does appear to be the case.

There is a procedure in one of the pdfs I have, involving replacing one of the transistors with a resistor and measuring the HV at around -900V, but before I do that and start working backwards, I wonder if you know of any stock faults or easy checks, that would make finding the fault a bit quicker?

Regards,

Alan.

[jopki]

Well done, it is a beauty! I got myself a dead 475 recently and all it needed for resurrection was a new quad diode rectifier on one of the negative power supplies and a bit of a wiggle of all socketed transistors and ics. It is just  slightly off calibration but you have now inspired me to finish the job  to make it perfect! Thanks!

Cheers, JE

[uktris]

Great restoration, been very helpful as I've just managed to pickup a bargain of a 465 w/DM44 from a lab clearance myself.

Got one dumb question for you though - how on earth did you get the vertical board out without mangling anything ? The only defect with the unit is that channel 1 V/div knob has become loosened from the switch cam but its proving hard to get at... I'm hoping its just some grub screws that need tightening much like the other switches...

Tris.

[ModemHead]

Got one dumb question for you though - how on earth did you get the vertical board out without mangling anything ? The only defect with the unit is that channel 1 V/div knob has become loosened from the switch cam but its proving hard to get at... I'm hoping its just some grub screws that need tightening much like the other switches...

You're testing my memory, but as I recall, the key for me was getting the 4 nuts off from inside the frame holding the BNC input jacks.  The BNC jacks do not need to be loosened, they're attached to this frame, not the front panel.  You can see these nuts after removing the two attenuator shields.  There are silver, cylindrical 3-legged capacitors in the way, but I discovered they're socketed and fairly easily removed.  (Don't swap these caps between channels.)  A nutdriver is essential to remove the nuts.  There was also a couple of flying resistor leads to be de-soldered at the front for the probe readout function.  There was a ground strap to be de-soldered from the bottom interface board.  Remove all the associated knobs and buttons from the front, disconnect the wires/cables and remove the screws from the board.  The whole assembly (pre-amp board, attenuator cam switches and the PCB they're attached to) can be lifted out.

Hope that helps!

[uktris]

Perfect thank you, I took a deep breath and whipped out the soldering iron and got it all apart
Strangely the actuators are the one piece of flimsy plastic in the entire unit - the v/div cam is only held onto the cam by an interference fit plastic piece which had sheared off...

Only one part that my photos couldn't work out on reassembly which is where the purple/black striped connector from the back of the vertical switch board goes (back of the board behind the main ribbon). I'm pretty sure it goes to the same connector on the interface board that the ribbon connector goes to but trying to trace it via the circuit diagrams.

[pyredex]

Is there any way someone could tell me where to start looking for problems with the crt? I was given this unit by my father in law, and it seemed to work for a minute or so then the screen went out.  Here is a picture or what it does when turned on.  Any help is greatly appreciated!

[albertr]

I'm trying to restore an old 465B I have got recently and need to remove and replace BNC jack for channel 2. Can it be replaced without removing preamp board? Does anyone have experience replacing BNC jacks on these old Tek scopes?

-albertr   

[TerraHertz]

It's great to see other people enjoying these old scopes. I generally prefer them to modern ones too, for multiple reasons. Apart from the lack of ability to save waveform images on disk.

One of the best things about this vintage of gear, is that back then the manufacturers were run by engineers, not marketing department and corporate extortionist droids. So they cared for their customers and believed the customers had a right to possess complete technical manuals, including full schematics and maintenance information.
The technical manuals from that era a wonderful thing to behold.

I just thought I'd mention, in case anyone reading this thread isn't aware of it, that it's still possible to obtain full service manuals for all these types of gear. Not just electronic copies, but actual paper originals, in good condition, for quite reasonable prices. There's a busy market in the USA for these manuals. They come up a lot on ebay, but there are also dealers who acquire these manuals in bulk from various sources, warehouse them, and have their inventory in online searchable databases.

Here's my list of old manuals sources. Over the years I've bought physical copies of the manuals for almost all the test gear I have, and find it's _very_ worthwhile to have them. Far easier to use paper copies, than to struggle with awkward poorly scanned pdfs. You just can't beat a big foldout schematic on the benchtop where you're trying to fix something.

Equipment manuals
-----------------
http://electronictrader.webserver.com.au/charles/bookhave.html
http://www.big-list.com/usedmanu.html  List of manuals dealers
http://www.w7fg.com/cgibin/cat.cgi?find=F   Manuals
http://www.agtannenbaum.com/   service manuals; radio,TV, VCR, as well as
     Antique, Amateur, Audio, and Test Equipment.
http://www.slack.com/manavail.html
http://www.spies.com/~dd/manuals.html
http://www.manualserver.com/hpmanuals5.htm
http://www.test.it/elettronica/MANUALS.HTML   All copies. Big range.
http://www.manualsplus.com/
http://www.magma.ca/~howardr/manuals.htm
http://www.fullnet.com/u/tomg/gooteesu.htm
http://www2.ocn.ne.jp/~handf/manual.htm
http://www.manualmerchant.com/
fanemerald2@yahoo.com  ebay testequip4sale
ebay: bkfowler  email: intvguy@cox.net
http://www.radioera.com/mall/newacquisitions.asp
http://www.sarrio.com/sarrio/hpmanuals.html
http://motocom.com/site_index.html  RepairManual.com  repair manuals for motorcycles, cars, trucks, tractors
http://www.manualscenter.com/  akai am-u02 $14

Your Manual Source <yms@usimperio.com>  (Carla)
http://www.usimperio.com/
http://www.consolidatedsurplus.com/search.htm  (Manuals)
  Consolidated Surplus
  P.O. Box 106
  Ellicott City, MD 21041
  410-685-1991

http://www.surplussales.com/Manuals/ManTestEqpt.html  Test Equipment
http://www.manualsplus.com  Manuals Plus Corporate Page
http://sphere.bc.ca/test/manuals.html Sphere's Used Electronic Test Equipment Information - Manuals and Parts
http://www.candrnet.com.au
http://www.macservice.com.au Macservice Pty Ltd
http://www.manualserver.com      MANUAL SERVER Automotive  aircraft electronics diagrams
http://www.manualserver.com/hpmanuals5.htm     HP Computer Manuals   HP54121Tscope
http://www.surplussales.com/Manuals/ManTestEqpt.html    Manuals: Test Equipment
http://www.yourmanualsource.com    Test Equipment Manuals Search Form
http://www.plotterpens.com/xypens.htm   imagingproducts1 XY Recorder Pens for obsolete HP
http://www.hi-manuals.com/index.html

http://bama.sbc.edu                    Boat anchor manual archive   DjVu format better than pdf!
http://bama.edebris.com/manuals/tek/   Mirror of same

http://manoman.sqhill.com/   manuals, online for free, plus lists of sources.
http://www.ebaman.com
http://www.ko4bb.com/manuals/
http://www.eserviceinfo.com

http://www.tech-man.com/   Technical Manuals Online
http://www.ko4bb.com/manuals/   Great! User uploads. Also Firmware.

ARTEK MEDIA HAS MOVED !!!!!! ( AND WE CHANGED OUR NAME)
New name:  ArtekManuals
New web:   www.Artekmanuals.com
New email: manuals@ArtekManuals.com

http://bama.edebris.com/manuals/tek/   free Tektronix manuals

edit to add:
http://www.ietlabs.com/pdf             Includes a lot of General Radio docs.
http://www.ietlabs.com/pdf/Manuals/

[ModemHead]

... Here's my list of old manuals sources. ...

I recently told another forumite that using the service manual to troubleshoot something 'felt like cheating'.

Thanks for compiling comprehensive list of very useful info.  Consider putting it in the EEVBlog Wiki?

[robrenz]

Awesome job ModemHead!  This is the thread I was thinking of when I said others have covered a lot of restoration stuff that I didn't bother putting in my 7603 restoration.  Nice descriptions of diagnosing and fixing the problems

[ModemHead]

Thanks robrenz. I really enjoyed seeing your handiwork as well.  I can't match your skill with metals and materials, mine still has a lot of 'character'.   But it still works great and it's the first thing I turn on when I just want to have a look at something.

[BMac]

Anybody got a source for vintage tektronix knobs for my 485, need CH1 & 2 Vertical Select.

366-1166-00 and 366-1338-00

Thanks!

BMac

[Ronbo]

Great post and nice work!  These scopes are real workhorses.  I bought mine used about 14 years ago from a guy in Dayton, Ohio that worked at NEC and he had about 10 of them he obtained as surplus.  I drove up from Cincinnati and got to take my pick from a stack he had in his garage.  Super nice guy.  If I remember right I paid around $125, and as I was leaving he reached in to a box, grabbed some probes and said "here, take these". 

When I got home and unloaded things I noticed that along with the pair of regular 100 mhz probes, he had thrown in a Tektronix current probe.  I listed it on eBay and the sale covered the cost of the scope and then some.  It was a lucky deal.

Anyway, this thing is still chugging along, and the only thing I've done use some deoxit on a few of the contacts.  One of these days I'm going to give it a good cleaning and alignment...

   

[PaulAm]

Is there any way someone could tell me where to start looking for problems with the crt? I was given this unit by my father in law, and it seemed to work for a minute or so then the screen went out.  Here is a picture or what it does when turned on.  Any help is greatly appreciated!

Probably an open filter cap.  Check all the power supply voltages.  You can get a service manual free online

[Giddie]

I got hold of an old Tektronix 466 (the Analogue Storage model).  The eBay listing gave the impression (to me, at least) that it was in working condition, if a bit worse for wear.  However, there's a lot of very nasty corrosion inside and it's developed several faults in transit (presumably).  I'm making slow progress, but my main concern is that almost all the push-switches are so badly affected by corrosion that they barely give at all when I push them.  Does anyone know if there's anything that can be done to replace them, or even take them apart and fix them?

[frank58]

May anyone help me with my tek 465 m ?
I have switch on it after a long time.
I have the settiings how in figures, the traces are that.
May the problem to be the settings ?
Thank for help

[Giddie]

I had a similar issue that I just fixed in my 466, and I think it must be a very similar thing that's happened to you.  In the 466, there's an axial electrolytic that filters the power rail in the horizontal amplifier circuit.  Because it was old, it had leaked, which had caused a nearby resistor to corrode and go open-circuit.  The resistor was just before the horizontal amplifier calibration pot, so the open-circuit was basically forcing the horizontal gain to just below its absolute minimum calibration point.  I believe it was a 220? resistor.  Maybe worth a check?

[Dick]

Beautiful job. Great looking lab. Really appreciate the quality of your photography! Your work give me courage to remove the froont-end board. My high voltage quit. ie -2500 reads -50V. I bought the scope in 1967! Thanks again  dick

[Dick]

Trying to remove the vertical pre-amp board. Doing it per manual but got to the point where it says to disconnect the Delay Line.
This looks tricky ie it's soldered in or am I missing something? I can see from your post,which is beautiful, that you did it
Looks like a solder sleeve and two conductors into the board. Would appreciate your comment.  dick hoffman

[ModemHead]

The delay line is the easy part.  Just unsolder the shield tabs.  A solder-sucker will help.  The two conductors go into sockets just like the coax peltola connectors, so the they will pull right out.

[FStephenmasek]

Thanks for this helpful thread!   I do not think mine 465 is working properly.  I collect and restore old radios.  Trying to use it to align FM radios, the trace is fuzzy and not shaped properly.  Trying to align and AM radio today, I have two traces when there should be one. 

Do you know of any good Tektronix service places in southern California?
 

[Dick]

Got the vertical preamp board off after fighting the nuts on the BNC connectors.  Verified the Voltage Multiplier is shorting.  Would appreciate any help on how I remove and replace it  dick

[Filter_head]

I have a 465 that recently developed a vertical deflection symptom.  The vertical position knob, both CH1 and CH2, has limited amount of vertical adjustment.  For example, turning from hard left to hard right will deflect the rastering beam about 1.8 div max. out of the 8/div total on the screen. 

Can't center the rastering beam on the center of the display either.  Horizontal display, time/div appears fine. 

I have a 465 I can scavenge for parts (dead CRT) and though about swapping the vertical deflection board.

Any other suggestions ladies and/or gents?

[w2aew]

Check all power supply voltages in the vertical amplifier and deflection amp circuits first.  In the few times where I've come across a restricted or shifted vertical or horizontal range issue, it's mostly come down to a power supply issue.

[Filter_head]

Check all power supply voltages in the vertical amplifier and deflection amp circuits first.  In the few times where I've come across a restricted or shifted vertical or horizontal range issue, it's mostly come down to a power supply issue.

Thank you, will report back with findings.

[Whuffo]

Thanks so much for the lovingly detailed description of your rehabilitation of this classic. I remember when they were new and how I lusted after one. Then during my field service days one of these traveled around the US with me. My how things have changed - but I'll always have fond memories of the 465.

[Filter_head]

Check all power supply voltages in the vertical amplifier and deflection amp circuits first.  In the few times where I've come across a restricted or shifted vertical or horizontal range issue, it's mostly come down to a power supply issue.

Taking the cover off and turning the unit on, a faint "sizzle" is heard in close proximity to the toggle switch adjacent to the PS transformer.  The sizzle sound fades after 4-5sec.  Switching the unit on and off can restore the sizzling noise.  The PS caps are directly behind the switch. 

[Filter_head]

Check all power supply voltages in the vertical amplifier and deflection amp circuits first.  In the few times where I've come across a restricted or shifted vertical or horizontal range issue, it's mostly come down to a power supply issue.

Low voltage PS magnitudes at the 5 TPs are all ok but the ripple is excessive in all of them (4-5X higher than spec).  Ripple in 110V is close to 100mV (spec 20mV).
Replacing the caps will improve that.

Measured the voltages in the Vertical Amplifier, deflection plates (spec 34V, top and bottom), measured 34.1V and 32.7V, respectively.



 

[SLJ]

Excellent job on bringing this one back.  My 465 is my favorite on the bench.

[Whuffo]

Check all power supply voltages in the vertical amplifier and deflection amp circuits first.  In the few times where I've come across a restricted or shifted vertical or horizontal range issue, it's mostly come down to a power supply issue.

Low voltage PS magnitudes at the 5 TPs are all ok but the ripple is excessive in all of them (4-5X higher than spec).  Ripple in 110V is close to 100mV (spec 20mV).
Replacing the caps will improve that.

Measured the voltages in the Vertical Amplifier, deflection plates (spec 34V, top and bottom), measured 34.1V and 32.7V, respectively.



 

Check / replace those filter caps - they're well past their "best by" date. Pay close attention to the dipped tantalum caps, they're known to be trouble in these scopes.

[Filter_head]

I did find the problem in my particular 465.

A faulty film resistor in the first V to I stage of the amplifier board.

Couple of photos here.  Replacement of the R4421 realized a fully functional amplifier board.

http://www.northreadingeng.com/Forums/index.php/topic,62.0.html

[Wire Nut]

Guys,
I know this is an old post... but I just got a 465 that is in good shape physically. It has manuals and probes; but no trace. I saw this post and it gives me a few things to look for, but first I need to get the cover off! Could someone be kind enough to tell me what to do? I only see two screws on the back and thought if I took those out maybe it would slide back and expose the guts- no such luck!
Thanks for any help you can provide.

[Andy Watson]

I only see two screws on the back and thought if I took those out maybe it would slide back and expose the guts-

Plus four screws in the feet/cable holders.

[Chipguy]

Nice restoraton !
I hope it will run without hassle for a long time 

[Martini]

I got extremely lucky yesterday: someone gave me a 465

I took the cover off today to replace the power cord (it's from Switzerland and I live in France). I saw these two heatshrink tubes hiding something:




...what is it? Should I preserve it?





Also, I'd like to understand to what extend the regulating range does affect the scope.

EDF is giving us around 235V, am I right to assume the M position to be adequate?

[alsetalokin4017]

Aren't those just the splices where someone before you has replaced the power cord already?

[Martini]

Correct. I didn't think it was the mowt elegant solution so I replace the wires from the switch up.

Now it's alive (although a bit sick):

[Ronbo]

Looks very clean Martini, shouldn't take too much work.

[Martini]

Cosmetically, it looks very good.
It's clean and all the knobs are intact.


The calibrator shows the square wave:




Changing the timebase, it doesn't look so good:




And the triggering doesn't work as smoothly as it should (provided I understood its principle):




Obviously, channel 2 doesn't work:





I guess I'll create a new topic to seek your help guys.

[tautech]

Cosmetically, it looks very good.
It's clean and all the knobs are intact.

I guess I'll create a new topic to ssek your help guys.

In the "Repair" board would be best. 

[hornm]

Hi,

I'm aware that this thread is quite old but did that service manual ever get posted?  I've tried to look for it but have not had too much luck.  I recently bought a 465 scope and it also has no trace except when I press the beam finder.  I've reset all components I could remove and found a ground plane wire that became loose and tacked that back on but still am not getting that trace.  I would appreciate that service manual so I can have a more professional approach to solving this fix.  I also need to get a few replacement parts.

Thanks

[w2aew]

Hi,

I'm aware that this thread is quite old but did that service manual ever get posted?  I've tried to look for it but have not had too much luck.  I recently bought a 465 scope and it also has no trace except when I press the beam finder.  I've reset all components I could remove and found a ground plane wire that became loose and tacked that back on but still am not getting that trace.  I would appreciate that service manual so I can have a more professional approach to solving this fix.  I also need to get a few replacement parts.

Thanks

It can be found here:
http://w140.com/mmm/tek-465-late.pdf
which is on this page (with a few more links):
http://w140.com/tekwiki/wiki/465

Note the the 465B is different, so be sure you have a non-B for the above links. 

[jh15]

How are you coming along on this?

I have a 465 non-B also but it is ok although a bit old in the crt teeth.

I am retired from the grind, but was a test equipment department tech, boss, slave for avionics companies.

Found a way to heat my basement, so have 535, 575 curve tracer, 555, other storage Teks and HPs to play with during blizzards.
Don't plan to run any on UPS's.

[Martini]

I didn't touch it. I have a question, though...is the red grid supposed to be lit? If so, what's the most common issue with it.

[Gerry Powell]

A friend and I are trying to repair his newly acquired 465 and have found a problem. The sweep variable red knob has taken a bump and it's depressed so far that you can just barely grab it to turn so I think the component it's connected to is damaged.
The main sweep works fine, but when the variable is turned the sweep disappears.
From what I can make of the manual, the variable sweep control is a pot ganged with a switch and it looks like the part number is 311-1701-00.
Any help appreciated.
thanks, Gerry

[pez.diSpencer]

Wow, thanks for posting this and great work! The Tek465 has always been the image in my mind whenever someone mentions a scope, and I finally found one on ebay (😬) for a very good price, non-working. Definitely a gamble as it doesn't power-on, so I'm hoping major components aren't pulled (😰)...but the price was too good to pass up-- fair enough for the spare parts if it's deader'n dead, at least. I'll post the condition when it gets here, and I'll start another 465 restore thread if the job can be done!

[P90]

Tektronix orgy? lol

https://orangecounty.craigslist.org/ele/6148052200.html

[pez.diSpencer]

Tektronix orgy? lol

https://orangecounty.craigslist.org/ele/6148052200.html

I saw that on ebay too... Wish I was in California instead of Chicago (which is the case six months out of the year, regardless)!

The guy selling those also designed and sells a nifty and compact pyramid step generator for checking/calibrating your scope's horizontal timebase.

http://m.ebay.com/itm/CALIBRATION-AND-TESTING-DEVICE-FOR-TEKTRONIX-AND-ALL-QUALITY-OSCILLOSCOPES-/131782800534?hash=item1eaeddf496%3Ag%3AeAEAAOSwgApXCtGO&_trkparms=pageci%253A0c73d5e7-4544-11e7-8d50-74dbd180b80b%257Cparentrq%253A59c0bd7815c0a88bc6508856fffcad63%257Ciid%253A12

[Martini]

Wow, thanks for posting this and great work! The Tek465 has always been the image in my mind whenever someone mentions a scope, and I finally found one on ebay (😬) for a very good price, non-working. Definitely a gamble as it doesn't power-on, so I'm hoping major components aren't pulled (😰)...but the price was too good to pass up-- fair enough for the spare parts if it's deader'n dead, at least. I'll post the condition when it gets here, and I'll start another 465 restore thread if the job can be done!

Nice, welcome in the family!

[pez.diSpencer]

Update: resurrected that dead 465!

https://www.eevblog.com/forum/repair/another-tektronix-465-oscilloscope-repair!-(and-a-question)/

[lowimpedance]

Shame all the nice pictures from the beginning of the thread of the restoration are now all gone  .
The perils of external hosting ruining the intent of this thread. Even though its an old one, it has surfaced again but now missing important detail.

EDIT , Nice to see the original pics restored in all their glory and this thread now complete again.   Thanks Modemhead.

[tautech]

Shame all the nice pictures from the beginning of the thread of the restoration are now all gone  .
The perils of external hosting ruining the intent of this thread. Even though its an old one, it has surfaced again but now missing important detail.

Yep, I thought so too and PM'ed the OP yesterday.

[j@cs]

That's awesome job you did. I own one of these beauties and reading your post I decided to clean my tektronix 465. But, when I tried to remove the front panel I just couldn't remove the push buttom for 20BW limit, and also  the delay time position knob and the time scale knob.  Can you show me the way?
Also, I bought my scope with some leds burned out or missing. The power led and the triggering leds are missing (are they incandescent lamps? Can I just solder a led on the board?) - Finally those leds from ch1 and ch2 rotary switch aren't glowing. Those I did't reach yet. Are they easy to be replaced?

Thanks a lot for you post and any help you can give me.